title: MAPKs ERK and p38, but not JNK phosphorylation, modulate IL-6 and TNF-α secretion following OK-432 in vitro stimulation of purified human monocytes.
abstract: Interaction between the immune system and cancer allows for the use of biological response modifiers, e.g. OK-432, in cancer therapy. OK-432, penicillin-killed Streptococcus pyogenes, is used in treating carcinomas, but also lymphangiomas. We have studied the role of monocytes (MOs) in the immune response to OK-432 by examining IL-6 and tumour necrosis factor (TNF)-α secretion after in vitro MO stimulation with OK-432, to some extent in comparison with lipoteichoic acid (LTA) and lipopolysaccharide (LPS). LTA stimulation of whole blood gave IL-6 but not TNF-α secretion, as previously shown with OK-432 stimulation, whereas both cytokines were secreted following LPS stimulation. Addition of the MAPK kinase (MAPKK) MEK inhibitor U0126 inhibited IL-6/TNF-α secretion in a dose-dependent manner. Flow cytometry and to some extent Western blot (Wb) analyses showed that MAPK ERK, located downstream of MEK1/2, is predominantly phosphorylated at isolation from peripheral blood. Addition of the p38 MAP kinase inhibitor SB202190 decreased MO IL-6/TNF-α production upon OK-432 stimulation in a dose-dependent manner. Addition of the MAPK JNK inhibitor SP600125 did not systematically change the MO IL-6/TNF-α OK-432 response. Flow cytometry showed that when stimulating the MOs before isolation from blood, LPS yielded ERK phosphorylation and LPS/LTA p38 phosphorylation, whereas OK-432 had no effects on phosphorylation levels. In conclusion, we have shown that OK-432 resembles TLR2 more than TLR4 stimulation of MOs and depends on MAPKK MEK and MAPK p38, but not on JNK phosphorylation. The MEK and p38 MO OK-432 stimulation dependence is possibly related to the differentiation of cells of the MO lineage.
authors.affiliation: Department of Surgical Sciences, Faculty of Medicine, University of Bergen, Bergen, Norway.
authors.forename: C
authors.initials: C
authors.lastname: Olsnes
authors.forename: J
authors.initials: J
authors.lastname: Olofsson
authors.forename: H J
authors.initials: HJ
authors.lastname: Aarstad
mesh_terms: D000873:Anthracenes; D000970:Antineoplastic Agents / Q000494:pharmacology*; D002070:Butadienes / Q000494:pharmacology; D002478:Cells, Cultured; D004791:Enzyme Inhibitors / Q000276:immunology / Q000494:pharmacology; D006801:Humans; D007093:Imidazoles / Q000494:pharmacology; D015850:Interleukin-6 / Q000096:biosynthesis / Q000276:immunology* / Q000378:metabolism; D007963:Leukocytes, Mononuclear / Q000187:drug effects* / Q000201:enzymology / Q000276:immunology; D008070:Lipopolysaccharides / Q000276:immunology / Q000494:pharmacology; D020928:Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000276:immunology*; D009570:Nitriles / Q000494:pharmacology; D010766:Phosphorylation; D010844:Picibanil / Q000494:pharmacology*; D011725:Pyridines / Q000494:pharmacology; D013682:Teichoic Acids / Q000276:immunology / Q000494:pharmacology; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis / Q000276:immunology*
chemical_list: D000873:Anthracenes; D000970:Antineoplastic Agents; D002070:Butadienes; D004791:Enzyme Inhibitors; D007093:Imidazoles; D015850:Interleukin-6; D008070:Lipopolysaccharides; D009570:Nitriles; D011725:Pyridines; D013682:Teichoic Acids; D014409:Tumor Necrosis Factor-alpha; C113580:U 0126; C432165:pyrazolanthrone; D010844:Picibanil; C009900:lipoteichoic acid; D020928:Mitogen-Activated Protein Kinases; C090942:4-(4-fluorophenyl)-2-(4-hydroxyphenyl)-5-(4-pyridyl)imidazole